Problem: Solve for $x$ : $9\sqrt{x} - 3 = 7\sqrt{x} + 4$
Subtract $7\sqrt{x}$ from both sides: $(9\sqrt{x} - 3) - 7\sqrt{x} = (7\sqrt{x} + 4) - 7\sqrt{x}$ $2\sqrt{x} - 3 = 4$ Add $3$ to both sides: $(2\sqrt{x} - 3) + 3 = 4 + 3$ $2\sqrt{x} = 7$ Divide both sides by $2$ $\frac{2\sqrt{x}}{2} = \frac{7}{2}$ Simplify. $\sqrt{x} = \dfrac{7}{2}$ Square both sides. $\sqrt{x} \cdot \sqrt{x} = \dfrac{7}{2} \cdot \dfrac{7}{2}$ $x = \dfrac{49}{4}$